When seed storage proteins change state

Proteins stored under extreme conditions

Unlike milk or egg proteins, which naturally exist in highly hydrated environments, plant storage proteins are accumulated in seeds at extremely high concentrations. They assemble into specific structures known as protein bodies, where they progressively transition from a hydrated and dynamic state to a dense, solid state.

While this change of state is essential for seed survival, the molecular mechanisms governing the assembly and organization of storage proteins remain largely unknown. Understanding how these proteins organize and stabilize under low-hydration conditions represents a major challenge at the interface of plant biology and physics. This key transition, essential to seed function, lies at the core of the MICROSEED project.

Reconstituting protein state transitions in the laboratory

The MICROSEED project aims to understand how plant storage proteins self-assemble, interact, and reorganize as water is progressively removed and subsequently reintroduced. To achieve this, the project combines approaches from protein biophysics, soft condensed matter physics, and advanced microfluidic technologies.

Membrane-based microfluidic microreactors will be developed to precisely control protein concentration, pH, ionic strength, and hydration level, using volumes on the order of tens of nanoliters. These devices will make it possible to reproduce in vitro the dehydration and rehydration cycles observed in seeds, while monitoring protein structural organization and dynamics across multiple length scales. These experimental approaches will be coupled with numerical modelling to better understand the driving forces underlying protein assembly.

Implications for seed biology… and for food science

By studying a diverse set of proteins from cereals, legumes, and oilseed crops, the project seeks to identify physical principles common to their behavior. These insights are essential for advancing our understanding of seed biology, but they are also highly relevant to food science. Gaining a better understanding of how plant proteins assemble during drying and how their properties evolve upon rehydration should help clarify their solubility and functional behavior, thereby supporting the development of more sustainable plant-based foods.

An interdisciplinary collaboration supported by the ANR

To address these objectives, the MICROSEED project brings together four scientific partners with complementary expertise: BIA (Biopolymers, Interactions and Assemblies), specialized in plant protein science; LOF (Laboratory of the Future), expert in microfluidics and soft condensed matter physics; LGC (Chemical Engineering Laboratory), specialized in colloidal physics and numerical modelling of complex fluids; and UMR STLO (Science and Technology of Milk and Eggs), focused on protein behavior in dense phases, with specific expertise in the drying of dairy and egg proteins.

Funded by the French National Research Agency (ANR) for a duration of four years, the MICROSEED project relies on physics-inspired approaches to better understand living systems, from seeds to food applications.

Project information

• Project start: October 2025
• Project duration: 4 years
• Coordinator: Adeline Boire (BIA)
• Partners: BIA, LOF, LGC, UMR STLO